This invention relates generally to crop harvesting and threshing machines, more commonly known as combines, and, more particularly, to the apparatus used to control the movement of the unloading auger by which clean grain is unloaded from the grain tank to a receiving vehicle. Specifically, the invention is directed to a control mechanism which permits the combine operator to start the engine on the combine only if the unloading auger control is in a predetermined position prior to the combine being started. Should the unloading auger control not be in the predetermined position, the safety switch breaks the starter circuit and prevents the combine from being started. This invention is applicable to all types of combines which utilize some type of a grain unloading tube that must move between predetermined positions of non-operation and operation.
Traditionally, combines utilize a grain storage system that has the threshed and cleaned grain transported by means of a collection trough and an auger to an elevator which carries the cleaned grain upwards into a receiving receptacle or grain storage tank. The grain is continuously fed into the grain tank during the operation of the combine as it harvests and threshes crop material in a field. The continuous field operation of a combine is generally limited by the capacity of the grain tank to store the cleaned grain. When the grain tank is full, the combine operator must normally cease the harvesting and threshing operation to unload the grain from the grain tank to a receiving vehicle. Occasionally, this unloading operation is conducted simultaneously with the continued harvesting and threshing by having a receiving vehicle move alongside the combine as it progresses down the field. The receiving vehicle may either be a wagon towed behind a tractor or a large grain truck. These receiving vehicles haul the loaded grain to appropriate storage areas generally remote from the field. This procedure is repeated continuously during the harvesting and threshing of the crop material. Combine operators normally activate the unloading system by engaging a lever or control which requires that the operator continue its engagement during the entire time that it takes the unloading tube to swing between its inboard and its outboard positions. Recently, control systems, such as that disclosed in U.S. application Ser. No. 059,852, filed July 23, 1979, and assigned to the assignee of the present invention, have been designed for combines which require the operator to momentarily engage a control mechanism which then automatically controls the movement of the unloading auger between the inboard and the fully outboard positions. The development of this type of a system has greatly simplified the number of operator functions that must be performed during the unloading of grain from the grain tank, especially if the unloading is done on the move.
However, this new type of unloading auger control system also presents a potential problem from a safety standpoint. Since the sub-systems on a combine will normally only operate when the engine is running or the ignition switch is turned to the on position, it is possible for an operator to accidentally engage the unloading auger control when the combine is not running or the ignition switch is not turned on. Additionally, since combines are present on farmsteads where it is common for children to climb on the parked machinery, it is plausible that the unloading auger control could be actuated by a child while within the operator's cab. Should this happen, it is possible that the operator would not know that the control has been actuated prior to his attempting to start the combine or turn the ignition switch to the on position. Should the combine be parked within an enclosed structure or near any type of obstruction in the path of the unloading auger as it moves between its inboard and outboard positions, the turning of the ignition switch would automatically start the unloading auger moving between its inboard and outboard positions. Obviously, since the unloading auger is of considerable mass, the movement of the unloading auger could cause severe damage to any object in its path. Alternately, should any obstruction be of substantial strength, such as a large tree or a supporting girder of a building, there could be substantial damage inflicted on the unloading auger. The foregoing problems are solved in the design of the machine comprising the present invention by preventing the combine engine from being started or the ignition circuit from being energized and the unloading auger from being activated to move between its inboard and outboard positions unless the unloading auger control is in its predetermined position prior to the ignition switch being turned to the one position by the combine operator.